Cupola furnace ?

Discussion in 'Furnaces and their construction' started by DavidF, Mar 20, 2019.

  1. Melterskelter

    Melterskelter Gold Banner Member

    Sweeping may not be wasted time—-quite a few crumbs of useful information might be in the dustpan by the time you finish.:)

    Denis
     
    Petee716 likes this.
  2. DavidF

    DavidF Administrator Staff Member Banner Member

    Well said!!
     
  3. Petee716

    Petee716 Gold Banner Member

    That's how I started in my trade. No regrets!

    Pete
     
  4. ESC

    ESC Silver Banner Member

    I joined C.W. Ammen's Backyard Foundrymans Society in 1996. He put out a 30 page newsletter for almost two years with reprints of articles he had written and some guest authors. In the summer of 1996 there was coverage of The Second International Conference on Contemporary Cast Iron Art from 1994 by David P Anderson. It was held at the University of Alabama at Birmingham and the Sloss Furnaces Historic Landmark. At the end of the article he mentions the worlds smallest cupola contest with about a dozen participating. The rules called for molten iron within 90 minutes from a cold start and the winner had a cup of molten iron in 30. The photos are black and white and pretty dark, but the winner looks like the one you posted above. The Society ceased to exist in late 1997.
    There was also an article by Stewart Marshall describing construction of a 7" bore cupola. I bought my copy from Lindsay, and don't know if it is still available. Like Ironside mentioned, they are labor intensive since they are continuous melt furnaces. I attended a workshop at the Knight Foundry in Sutter Creek where they ran a cupola and it seemed like it took an experienced five man crew plus the attendees.
     
    DavidF likes this.
  5. Tony

    Tony Copper

    Why not run the cupola continuously into a holding furnace and take taps from that?
     
  6. OMM

    OMM Silver

    This is huge! Can you share with us the pattern you plan on pouring?

    A +200 pound pour, IMO requires some really big friends that like to hustle. I can see you doing a 200-300 pound pour using two furnaces and one helper (and maybe with a radius crane you could do this by yourself).

    Maybe take your pattern to the local pour and see if you will be the debut.
     
  7. DavidF

    DavidF Administrator Staff Member Banner Member

    I havent made the pattern yet, but it would be an engine block.
     
  8. OMM

    OMM Silver

    That would be interesting. Is it for a one off or multiple runs?

    At the very end of my bucket list is a small steam engine, (maybe 2-3 piston) powered from a rocket stove.

    You got some high aspirations!
     
  9. Melterskelter

    Melterskelter Gold Banner Member

    Ya, might as well try something simple:p

    Denis
     
  10. DavidF

    DavidF Administrator Staff Member Banner Member

    It would probably be a one off and would be done in lost foam. I would be taking the internals from a mercruiser 470, which is a 4 cylinder 3.7 liter based off half a a 460 for engine and fitting them into a Model A engine block, or one that looks like the A engine block externally in this case. Model A engine are a 3 main block with a crankshaft that looks like someone took a dumbbell bar and bent it into a crankshaft. Thats actually basically what they did LOL. The mains are gravity fed oil and the rods are splash lubrication.
    The 470 has a beautiful cast crank with counterweights and 5 mains. it uses 460 pistons and rods pressure fed mains, and pumped out 190 HP with a 4bbl carb.

    It actually a pretty simple casting all things considered. Worst part would be the cooling passage core. It was not held in by core prints, it was "nailed" in....
     
  11. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    That's a big 4-banger and a lot more twist than a model A.

    Famous last words :). It'd be a great project......hard to pull off. How many iterations/times would you be willing to try it? As committed as I am to lost foam, I think printed PLA and block investment might have a better chance of early success and you could string supporting wire chaplets through all the cores before investing it. A lot of dough for pattern and mold materials though compared to LF. It would have the added complication of a big burnout oven but that's just some wire support, ceramic fiber, and a couple good burners. Rigging yourself up a ladle and pouring it would also take some doing.

    Yah, because whether loose sand coated lost foam or bound core, you still have to get the gas out of there.

    Best,
    Kelly
     
  12. DavidF

    DavidF Administrator Staff Member Banner Member

    Id only have to do it once provided I say the magic words "Hmm I dont think that went well at all" Right after the pour... :p
     
    Tobho Mott likes this.
  13. Tobho Mott

    Tobho Mott Gold Banner Member

    Like a deathbed confession, I think you might have to really mean it when you say that, for it to actually work...

    Cant hurt to try though! :D

    Looking forward to seeing the cupola build as well as the casting!

    Jeff
     
  14. crazybillybob

    crazybillybob Silver Banner Member

    Can I ask that you video the pour! please :)
     
  15. DavidF

    DavidF Administrator Staff Member Banner Member

    I will, but it wont be something that happens any time soon. Maybe in the next 2 years. Right now I would just like to get the cupola built over the winter......
     
  16. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    In some respects it's fun to think about such a project but in other respects, even after you've built that cupola, quite daunting just because of the scale challenges for hobbyist. If I think about my castings and lost foam process for 20lb aluminum parts and try to apply that to a 200lb iron pour and part like an engine block, making and coating the pattern seems the least of the challenge.

    I have a 30 gal drum for a lost foam flask and that's 300+lbs of mold media (I figure about 60lb/5gal bucket on sand). For that engine block I'd say 500-750+ lbs of mold media plus the weight of the flask, which would probably need to be a steel box, maybe the size of a small dumpster, of fairly significant weight by itself. You might also need to make it a vacuum flask and need a big vacuum source. Then you'd have to be able to vibrate 1/2 ton+ mold and flask at fairly high excitation to pack it well, taking care to fill it very carefully and uniformly so as not to distort the foam mold. After you add a couple hundred more pounds of molten iron you need to dump a 1200lb+ mold after it freezes and cools.

    If you think you could get that block and pattern with gating into a 55 gal drum that would probably be about 650lbs before it was poured.

    A 200lb iron pour with weight of the ladle and shank in my mind is approaching the limit for a 2-man pour but then imagining the top of the mold being 3ft or more above ground level makes me think you're building a tilting pouring ladle and lifting apparatus. -Then shaking out and degating a 200lb casting. That's a lot of work for one part my friend. I must be (am) getting old or you've been on your tractor and new acreage long enough that everything looks small and light by now.o_O

    Might make more sense to just print the pattern and core boxes and do the mold and cores in bound sand.......iterations would be more palatable as would subsequent copies of the part.

    All that said, I'll buy the beer and popcorn.....have at it. It would be epic.

    Best,
    Kelly
     
  17. Melterskelter

    Melterskelter Gold Banner Member

    Wow! That was amazing bound sand work. Is there more info about pouring the mold? Did it pour right the first attempt? The PAIN of it if it did not! In looking at the site I conclude this is a (limited) production block—-yes?

    Denis
     
  18. Their website doesn't directly link to it (that I could see) but a quick search brought me to this page: https://healeyfactory.com.au/servic...engine-development-and-manufacturing-process/
    and then to this page: https://healeyfactory.com.au/services/dmd-australia/dmd-casting-process/

    There's no way I would attempt such a casting with green sand, resin sand solves too many issues and makes life easy. The block is 45+ Kg, so well within the realm of two guys pouring the block together.
     

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